The company announced the surprise news in a statement issued at 8.45 this morning.
It said Ashley, pictured below, had agreed with the board that he will not put himself up for re-election at the company’s forthcoming annual general meeting on 5 June.
David King, currently chief financial officer, will take over as CEO following the AGM.
The statement said: “Ashley is leaving for family reasons and in order to fulfil his plans to transition to a be a ‘plural’ non-executive director as the next phase of his career.
“As a result of Ashley’s resignation, Johnston Press will appoint David King, currently chief financial officer, to replace Ashley as CEO. David will step into the role of CEO with effect from the AGM. David’s replacement will be announced in due course.”
Said Ashley: “I have been privileged to lead Johnston Press during a period of unprecedented turbulence in our industry. Since 2011 we have grown our overall audience in particular our digital business, created an industry leading tele-sales operation and maintained margins.
“The acquisition of the i newspaper has been a particular highlight. I am proud of what the Board and my colleagues have achieved and would like to thank them all for their support. I wish David every success in his new role.”
Johnston Press chairman Camilla Rhodes said: “On behalf of the Board, I would like to thank Ashley for his significant contribution since becoming CEO in 2011. We are sorry that he felt that his personal circumstances required a change at this time.
“Ashley oversaw the successful acquisition of the i newspaper, has driven growth in our digital footprint, while making substantial progress in reorganising and restructuring our business. We wish him every success in the next phase of his career.
“I am pleased to announce that David King will step up to become CEO. David has worked closely with the Board on our strategic review of financing options.
“I am confident that David will prove to be a strong leader and his transition to the CEO role provides stability to the business at this important time.”
Ashley joined JP as chief executive in November 2011 from technology giant Microsoft where he was vice-president with responsibility for its UK consumer and online businesses, including Microsoft News (MSN.)
Before that he had worked as a director of new media and technology at the BBC where he oversaw the launch of the BBCiPlayer and was editor of BBC Online.
His position had been under threat last autumn after JP’s largest shareholder, the Custos group headed by Christen Ager-Hanssen, publicly called for former Local World and Metro boss Steve Auckland to be given the CEO role.
However speculation about a takeover bid by Mr Ager-Hanssen has since receded after an attempt to call an EGM of shareholders was ruled out on procedural grounds.